520T Battery Back Up, Extra Relay?

Allright.. This is my 4th car that I install alarm and this is my first time using 520T Back up. So please bear w/ me. I'm mating this 520T w/ Viper 791XV. Without 520T, the red wire will draw the power from constant + from constant wire on steering column fused. I assume that positive tail light output from the main harness should be connected directly to positive line that will flash the tail light to provide status of the vehicle. I've connected this for few days and I have no problem w/ this. Then I read 520T's install instruction: 2. Do not use 520T BBU to support parking light flash during remote start as the BBU can't even support the tail light output? Do I really have to switch the output + flash light out to negative to trigger an outside relay for use w/ the BBU? Or am I okay w/o putting on the relay when somehow my "real car battery" is being disconnected for service and the alarm is functioning?

You can leave it positive the only problem is that should the alarm be set off with the main battery disconnected the back up battery will die very quickly because it can't handle the current draw of the parking lights.  Depending on the curent draw of the lights you might get between 5 and 30 seconds from the battery before it dies completely.  So to answer your question you would be better off using an offboard realy to drive you parking lights.Cause I'm So white and nerdy...

First Class Certi-fried installer

Thanks for the reply.. Oh well.. Seems like I have to install the relay now :)

I wondered myself why it said do not use it to support parking lights during remote start. How would you be using the remote start function if your main battery was disconnected?Life moves pretty fast; if you don't stop and look around once in a while; you could miss it.

Yeah nice little misprint in the manual.  There's a surpise, a misprint in a DEI manual who'da thunk it?  The same sompany that in some of the quick refence diagrams still says that green is -lock and +unlock,  and blue is +unlock and -lock. Cause I'm So white and nerdy...

First Class Certi-fried installer

cntrylvr79 wrote:    The same sompany that in some of the quick refence diagrams still says that green is -lock and +unlock, and blue is +unlock and -lock.

That really puzzles me big time when I tried to hook that lock and unlock thing to my car. I installed Aladdin before and it was CLEARLY stated that there's another wire that if hooked up to a + then the green and blue = + and the other way around if you hook up w/ ground I had to actually hook up the alarm brain w/ the battery and test whether it's ground or positive.. :lol: